Kinshasa: The Congolese army clashed Monday with suspected Ugandan rebels blamed for two massacres in the town of Beni in the volatile east of Democratic Republic of Congo, a senior official said.

The rebels were "organising themselves" for another possible attack on the town -- the scene of two bloodbaths in almost as many weeks -- when troops came upon them, the governor of troubled North Kivu province Julien Paluku told AFP.

Soldiers freed a hostage, but the shooting stopped as night fell, he said. "We couldn't see the enemy... and we risked falling into an ambush."

The fighting erupted as families in Beni were preparing to bury the dead from the latest attack when 11 people were killed -- mostly hacked to death with machetes -- in a raid on Saturday night.

Only hours before President Joseph Kabila had left the town promising to defeat the rebels of the Allied Democratic Forces and National Army for the Liberation of Uganda (ADF-NALU), who have been terrorising the resource-rich region for almost two decades.

Outraged locals took out their anger at the repeated killings on Sunday by partially wrecking a roundabout in the town on which a statue of Kabila stands.

View galleryDemocratic Republic of Congo soldiers march on December&nbsp;&hellip;
Democratic Republic of Congo soldiers march on December 31, 2013 in Eringeti towards the front line …
As many as 30 people were killed on October 16 in another night-time attack on Beni, a major trading crossroads of half a million people.

"There was contact today with rebels on the outskirts of the town of Beni, inside the Virunga National Park," governor Paluku said, referring to one of Africa's best-known reserves which is also home to more than half of the world's 700 or so mountain gorillas.

The freed hostage was being interrogated to find out what the rebels were planning, he added. The military could not be contacted for further details of the clashes.

Civil society groups claim that 120 people have died in "successive massacres" in the past month around Beni committed by the rebels, who have been hiding out in the Ruwenzori mountains that straddle the border with Uganda since being driven out of the country by President Yoweri Museveni in 1995.

Fourteen people, including women and children, were killed with machetes last week in the Kampi ya Chui district, the groups said. Some had been decapitated.

The mainly Muslim rebels have been blamed for atrocities, pillaging villages and forcing locals to fight for them for years, while funding themselves from the lucrative smuggling of wood.

In January, the Congolese army and soldiers of the United Nations mission in the country, MONUSCO, began an offensive against the ADF-NALU, the last major insurgent group active in the region.

At the time, they thought they had been severely weakened them. However, the rebels have bounced back since the brutal death in August of Congolese army chief General Jean-Lucien Bahuma.

During his visit to Beni, Kabila called for further assistance from MONUSCO troops to defeat the rebels.

A curfew was also imposed on the town "because these people (the rebels) come and we don't know how to tell rebels from civilians," Paluku said. "That's how they operate."